The backbore of the mouthpiece influences its ease of play to a percentage equalling its percentage of length.

Most musicians are not aware of the importance of this part of the mouthpiece.

The mouthpieces are usually classified according to cup depth and rim width, and the only information one will get by looking through
the bore is the degree of pollution.

The shape of the backbore can hardly be determined with traditional methods as this bore is too long and narrow to be measured
exactly. People began to realise the importance of this part of the mouthpiece with the introduction of the screw-rim mouthpiece.

The mouthpiece works like a jet, its shape determines speed and intensity of the air compression inside the instrument, as well as the
resulting standing wave.

So, the musician can easily choose his/her ideal tone system. The relevant aspects for the musician's choice of the right shank should
be ease of play and desired tone colour. Sometimes it will be impossible to find all aspects embodied in one and the same mouthpiece. Our module system will satisfy the musician's demands to a
large extent.

In the following the number of the shank is inversely proportional to the volume of the shank. This means that number one is a bulgy
shank with a wide bore, whereas number eight is narrow and slim.

Wide shanks produce a full big tone, the high register is often hard to play. Narrow shanks produce bright and sharp tones.